1. Field of the Invention(s)
The present invention(s) relate to radio access networks and, more particularly, fronthaul networks used in radio access networks.
2. Description of Related Art
For scalability and rapid deployment purposes, communications carriers often implement their respective radio access networks (e.g., cellular networks, such as LTE and LTE-Advanced) using a split communications architecture, comprising a backhaul network and a fronthaul network. While the backhaul network generally provides data communication between a core network and sub-networks on the edge network (e.g., central office [CO]), the fronthaul network is meant to provide data communications between radio transceivers distributed at remote locations (e.g., remote radio heads [RRHs] on remote cell towers) and radio processing units (e.g., baseband units [BBUs] at a central office). Splitting radio transceivers from the radio processing units can not only permit pooling of digital resources with centralized radio processing (e.g., baseband processing), but also be cost effective, improve capacity, and improve performance in the resulting radio access network.
Often, the radio transceivers of the radio access network and their associated antennae are distributed a long distance (e.g. 1 to 10 km) from the radio process units, which are usually located at a central location. As such, to ensure transportation of radio frequency (RF) signals in real time, fronthaul networks traditionally rely on fiber optic connections that facilitate fast data rates and low latency. Each radio processing unit (e.g., BBU) is often connected to a radio transceiver (e.g., RRH) using a high speed interface protocol, called Common Public Radio Interface (CPRI), over a fiber optic connection.
Unfortunately, fiber optic connections are not as ubiquitously available as needed to implement a complete fiber optic-based fronthaul network for radio access networks. Additionally, implementing fiber optic connections is usually costly in time and money, especially with respect to radio transceivers of radio access networks, which are typically installed on building rooftops, towers, and the like.